1. Field of the Invention
The present invention relates to a control device and a control method of an engine.
2. Description of Related Art
It is known that the intake air amount of an engine, mounted on a vehicle, is adjusted by the throttle valve. Continued use of an engine may form a deposit on the throttle valve, sometimes resulting in a decrease in the intake air amount even when the throttle angle remains the same. Meanwhile, technology has been developed to correct the throttle angle according to the number of engine stalls or the engine speed and to store the resulting learning value for preventing permanent performance degradation.
The stored learning value may be cleared to the initial value, when the battery is removed or replaced for vehicle maintenance. In this case, if the throttle valve is replaced or cleaned, a desired air amount can be obtained sufficiently; however, if a deposit is remains formed on the throttle valve, the air intake amount will be insufficient.
As one of the methods to avoid the insufficiency of the intake air amount, Japanese Patent Application Publication No. 2010-127212 (JP 2010-127212 A) discloses a method. According to this method, if the learning value is cleared, the throttle valve is controlled so that the insufficiency of the intake air amount can be avoided when the engine is started later.